The MAC at Northwestern University is a truly multidisciplinary program that operates as an integrated unit under the leadership of the above-named professionals to address a broad range of research and training activities. Biomedical Research. The major focus is the study of immune- mediated inflammation in rheumatic disease. Five developmental/feasability projects cover this area: characterization of T-cell receptors of rheumatoid synovial lymphocytes to type II collagen (DF1); IL-1 and B-cell growth factor production by synovial large granular lymphocytes (DF2); macrophage heterogeneity in rheumatoid synovium (DF3); biology of CRP in rheumatoid synovium (DF4); and effect of adjuvant- induced arthritis on systemic bone mineralization (DF5). A second focus involves infectious agents in rheumatic diseases: one project will search for a retrovirus etiology in Kawasaki's disease (DF6). The third focus is the reconstruction of damaged joints: one project will study the strength of the cement/bone interface in cemented prostheses (DF7). Non-biomedical Research. Changing patterns of health care are being investigated for the effect of HMO growth upon referral utilization to the rheumatology subspecialist (C3); the cost effectiveness of rheumatologists as primary care providers for rheumatoid arthritis patients (C2); and the use of management technique, the Critical Path Method, to control inpatient costs of arthritis rehabilitation (C4). Children and the aged with musculoskeletal disease are being studied: children to treat pain with psychological approaches (C5) and to better understand their pain experience (C6); and a large cohort of aged to document the trajectory of functional status decline, health care utilization and costs (C1). Controlled prospective studies of treatment build upon current experience: the first looks at the effect of a shoe orthosis in rheumatoid arthritis (C7); and the second upon the effect of ultrasound therapy on knee contractures in osteoarthritis (C8). The education area extends current work in problem-solving education strategies; low impact aerobic exercise for arthritics and trained patient instructors to explore innovative educational methods for allied health professionals (E2); and a new ambulatory rheumatology elective for senior medical students (E1). Biostatistical and Data Management Core. This unit - a vital support for projects and a means to strengthen bonds among MAC investigators - provides services for all components of the MAC.